The purpose of this research is to evaluate the relationship between prior infection with the Epstein-Barr virus (EBV) and subsequent development of Hodgkin's disease (HD) through the identification and analyses of pre-diagnostic sera. Specifically, we will evaluate the presence and levels of antibodies to a variety of EBV antigens in pre-diagnostic sera of HD cases in comparison to appropriately matched controls. The specificity of the virus association will be evaluated by comparing the subjects for antibodies to other herpes viruses. The specificity of the disease association will be evaluated by making similar comparisons for individuals who subsequent to sera collection developed either leukemia or non-HD lymphoma. The method used is a collaborative case/control study. The source of subjects includes four populations from whom sera was collected and stored sometime in the past and who can be linked to either a cancer registry or to a medical record system. The long-term objective of this research is to understand the role of EBV in the pathogenesis of HD and to identify markers of individuals at high risk.